With expected heavy rains this El Niño season, we are reminded of our water challenges: too much rain in the winter, not enough in the summer. This is typical of our Bay Area Mediterranean climate, but with smart design and adaptation we can turn these challenges into opportunities. With the drought also in effect, what rainwater we do get, should be managed carefully. Rainwater harvesting and stormwater retention can be designed into our gardens and landscapes to minimize runoff and erosion and maximize water conservation.
Rainwater harvesting is a wonderful way to preserve the abundance of winter. It involves collecting runoff from surfaces such as roofs and storing it in a cistern. Catchment systems vary in capacity from a single 60-gallon barrel to large systems with thousands of gallons of storage space. Depending on your summer watering needs, it can take a pretty large system to collect enough rain water to completely provide for summer irrigation, but every little bit helps. Catching rainwater for later use is an important part of water conservation, and will play a growing role in our approach to water management as water demands rise and supply dwindles. Find out more on how you can minimize your summer watering needs and get the most out of your saved rainwater in the Bay-Friendly Gardening Guide.
Another way to save the rain and further reduce stormwater runoff is by designing stormwater management into our landscapes. Many of our Bay Area soils are high in clay and do not drain well. Planting native grasses and other plants with fibrous, deep reaching roots will increase airspace in such soils and greatly improve drainage. Feeding organic matter to our soils with compost and protecting soil surfaces with plant-based mulch further improves drainage and reduces runoff erosion. Using permeable materials for hardscapes, such as flagstone or brick-on-sand patios, allows water to percolate into the ground rather than run off into a storm drain. Including rain gardens and bio-swales further reduces runoff by creating on-site stormwater detention, slowing runoff and allowing recharge.
When we build rain catchment and storm water management into designs for our garden and landscapes, we can turn our climate challenges into opportunities. You can find out more about these topics by following the links below.
Smart from the Start
A California water conservation program that provides user-friendly tools and landscape templates to assist new homeowners and developers design and install beautiful, water-smart landscapes.
What is a Rain Garden?
A rain garden is a garden takes advantage of rainfall and stormwater runoff in its design and plant selection.
American Rainwater Catchment Systems Association (ARCSA)
ARCSA promotes sustainable rainwater harvesting practices to help solve potable, non-potable, stormwater and energy challenges throughout the world.
What is a Bioswale?
Also known as infiltration swales, biofilters, grassed swales, or in-line biorentention, bioswales are vegetated open channels specifically designed to attenuate and treat stormwater runoff for a defined water volume.